The present invention relates to a manufacturing technology of a semiconductor device, particularly to a technology effective when applied to the manufacture of an insulated gate bipolar transistor (which will hereinafter be abbreviated as IGBT).
In Japanese Patent Laid-Open No. 2003-59856 (Paragraph [0012], FIG. 5), there is described a technology which includes implanting impurity ions into the back surface of an FZ wafer and carrying out heat treatment for activating the implanted ions by using laser annealing with pulse laser having a wavelength of from 240 to 1070 nm and a half bandwidth of from 100 to 500 nm or using, in combination, this laser annealing and low-temperature furnace annealing.
In Japanese Patent Laid-Open No. 2002-314084 (Paragraphs [0027]-[0030], FIGS. 6 to 8], there is described another technology which includes grinding a surface opposite to a surface having an emitter electrode formed thereover to a predetermined thickness; selectively washing only the ground surface; implanting, into the washed surface, phosphorus ions for the formation of a field stop layer and boron ions for the formation of a collector layer; carrying out heat treatment at a temperature of 300° C. or greater but not greater than 550° C. to form the field stop layer and the collector layer; and forming a collector electrode.